Adverbial has 2 senses

• each year(r = adv.all) annually, every year, yearly - without missing a year; "they travel to China annually"
• each year(r = adv.all) annually, p.a., per annum, per year - by the year; every year (usually with reference to a sum of money paid or received); "he earned $100,000 per annum"; "we issue six volumes per annum"